gender and sexuality is a fickle thing. sometimes two gay cisgender men will be dating for decades and one of them will turn out to be a transgender woman. a lot of times that won't work out but sometimes it will. her partner may still choose to identify as gay. She might even identify as gay, and they continue to be happily in love. Queer politics isn't going to get any better if you don't accept that situations like that happen every day.
Their love doesn't get any less queer (as in dissimilar to 'the norm') just because they're """"""technically hetero""""""" now
It actually gets MORE queer, and we need to, we must, and we should celebrate and appreciate that regardless of whether that's the choice we would have made for ourselves